1. Field of the Invention
The present invention relates to a ferroelectric medium, a manufacturing method thereof, and an information storage device using the ferroelectric medium. In particular, it relates to a ferroelectric medium having an insulating layer which can prevent dielectric breakdown at a high voltage.
2. Description of the Related Art
As generally known in the art, ferroelectric material has a spontaneous polarity which may be reversed by application of an electric field. The ferroelectric media is a non-volatile recording media with a higher capacity and is used for recording, editing and storing information using the property of the ferroelectric material.
FIG. 1 illustrates a cross-sectional view of the conventional ferroelectric medium.
As illustrated in FIG. 1, the conventional ferroelectric medium includes a substrate 100, a bottom electrode layer 110 formed on the substrate 100, and a ferroelectric layer 130 which is formed on the bottom electrode layer 110.
In order to write/read the data onto/from the ferroelectric media, there are included a probe 20 for writing/reading the data onto/from the ferroelectric layer 130 in a contact or a non-contact manner and a scanner for actuating the probe 20. Further, the scanner includes a cantilever 21 for supporting the probe 20 and a microelectromechanical system (MEMS) actuator for actuating the cantilever 21.
However, in the conventional ferroelectric media having the above-described structure, there is the problem that dielectric breakdown often occurs in the ferroelectric layer, which is a thin PbTiO3 film, due to a strong electric field generated when a switching voltage of high potential is applied to the interface between the bottom electrode (Pt) and the ferroelectric layer (PbTiO3).